1. In Situ Evaluation Of Sodium Hexametaphosphate-Containing Dentifrices

In Situ Evaluation Of Sodium Hexametaphosphate-Containing Dentifrices

Reference: Wefel JS, Stanford CM, Ament DK, Hogan MM, Harless JD, Pfarrer AM, Ramsey LL, Leusch MS, Biesbrock AR. Caries Res. 2002;36(2):122-8.


Based on this research, sodium hexametaphosphate does not interfere with the normal fluoride activity of the toothpastes tested. Relative to the positive and negative controls, the experimental dentifrice with stannous fluoride was numerically better at inhibiting demineralization of sound root surfaces.


An investigator-blinded, in situ clinical study was conducted to evaluate the effects of two experimental dentifrice formulations containing sodium hexametaphosphate, an anticalculus/whitening agent, on demineralization/remineralization.


Experimental dentifrices were:

  • Stannous fluoride (SnF2) with sodium hexametaphosphate (Note: This was an early prototype of the eventual marketed stannous fluoride/sodium hexametaphosphate product.)
  • Sodium fluoride (NaF) and sodium hexametaphosphate

Both experimental dentifrices were packaged in a dual-phase tube

Three controls were used to evaluate the experimental dentifrice formulations’ ability to alter demineralization-remineralization:

  • SnF2-positive control
  • NaF-positive control
  • No fluoride placebo-negative control

The single-section crown model, developed at the University of Iowa, was used to evaluate the fluoride efficacy of the treatments.

The crown slot held:

  1. a sound root section;
  2. a root surface lesion section; and
  3. enamel surface lesion section.

Thirty subjects were randomized to one of 10 treatment sequences involving 5 dentifrice treatments. Each dentifrice was used twice per day for 1 month over the 5-month period. At the end of each leg, the gold crown was removed and replaced by a new crown with three new substrates.


Results suggested a clinical level of anticaries activity for the experimental SnF2 and NaF dentifrice formulations that was as good as either of the positive controls, when evaluated using polarized light microscopy.

Root Sections: Analysis of Variance

* Based on pairwise comparisons (P<0.05)

See publication for additional results.

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